Table 2.
Vital signs, exercise tests, and blood gas analysis.
| Baseline Zurich 490 m n = 6 | St. Moritz 2048 m Placebo n = 6 | St. Moritz 2048 m NOT n = 6 | |||
|---|---|---|---|---|---|
| Day 1 | Day 2 | Day 1 | Day 2 | ||
| Vital signs | |||||
| HR rest, 1/min | 64 (56; 78) | 66 (61; 77) | 71 (65; 76) | 70 (64; 72) | 70 (62; 78) |
| BP rest, systolic, mmHg | 114 (102; 142) | 127 (121; 135) | 127 (121; 135) | 125 (117; 132) | 121 (113; 141) |
| BP rest, diastolic, mmHg | 74 (71; 89) | 80 (72; 89) | 80 (72; 88) | 78 (71; 82) | 76 (69; 89) |
| SpO2 pre 6 MWD, % | 97 (94; 98) | 95 (88; 96)* | 95 (92; 95) | 95 (90; 97) | 95 (90; 95) |
| 6-minute walk test | |||||
| 6 MWD, m | 620 (563; 720) | 583 (467; 696)* | 563 (485; 653)* | 561 (501; 688)* | 572 (500; 691)* |
| HR end 6 MWD, 1/min | 94 (80; 106) | 104 (95; 123)* | 103 (84; 116) | 100 (95; 116)* | 108 (97; 149)* |
| BP end 6 MWD, systolic, mmHg | 150 (146; 155) | 175 (171; 186)* | 177 (170; 183)* | 175 (170; 191)* | 173 (153; 197) |
| BP end 6 MWD, diastolic, mmHg | 86 (77; 96) | 93 (85; 100) | 89 (79; 97) | 83 (72; 119) | 84 (72; 95) |
| SpO2 end 6 MWD, % | 87 (82; 92) | 83 (76; 87)* | 80 (73; 87) | 78 (69; 83)# | 80 (75; 87) |
| Borg dyspnea | 3.5 (1.6; 5.0) | 4.5 (3.0; 7.2) | 5.0 (3.0; 5.8)* | 4.5 (3.0; 6.0) | 4.5 (3.0; 7.8) |
| Borg fatigue | 2.5 (0.8; 4.5) | 5.0 (2.3; 7.0)* | 5.0 (2.3; 5.3) | 3.0 (2.3; 4.8) | 4.0 (2.3; 6.0) |
| Constant work-rate endurance test (CWRET) at 60% of Wmax | |||||
| Endurance time, s | 826 (243; 1410) | 200(160; 785)* | 424 (163; 694) | ||
| PaO2 end CWRET, mmHg | 59.7 (51.6; 67.4) | 53.9 (43.9; 63.9) | 54.6 (42.2; 60.7) | ||
| SaO2 end CWRET, % | 90.8 (87.1; 94.1) | 83.3 (75.2; 91.7) | 89.5 (75.7; 91.4) | ||
| Arterial blood gas analysis | |||||
| pH | 7.48 (7.42; 7.48) | 7.46 (7.44; 7.49) | 7.46 (7.48; 7.49) | ||
| PaO2, mmHg | 65 (60; 72) | 60 (54; 63) | 58(50; 61)* | ||
| PaCO2, mmHg | 32 (29–35) | 32 (29–34) | 33 (29–36) | ||
| Sleep study | |||||
| SpO2, % | 93 (91; 95) | 89 (85; 90)* | 90 (89; 92)* | 97 (95; 97)* # | 97 (95; 97)* # |
| ODI, 1/h | 10.4 (3.1; 26.9) | 34.0 (5.3; 81.3)* | 27.2 (6.9; 61.5)* | 0.3 (0.1; 2.3)* # | 0.7 (0.1; 4.0)* # |
| AHI, 1/h | 27.3 (17.5; 38.7) | 34.2 (13.3; 71.2) | 29.8 (16.5; 63.7) | 23.9 (2.4; 30.7) | 15.2 (7.7; 33.0)* # |
HR, heart rate; BP, blood pressure; 6 MWD, 6-minute walking distance; PaO2, arterial partial pressure of oxygen; PaCO2, arterial partial pressure of carbon dioxide; SpO2, oxygen saturation; ODI, oxygen desaturation index; AHI, apnea/hypopnea index.
*
Significant difference to low altitude baseline p < 0.05;
#
significant difference to placebo of the same night p < 0.05.